Structural member



W. F. DAVIS Feb. 21, 1939.

STRUCTURAL MEMBER Filed Nov. 12, 1956 '2 sheets-sheet 1 Patented Feb.21, 1939 UNITED STATES WilliamL F; Davis;

Sears, Roebuck and Co., Chicago, lll., a. corporation of New YorkAspiranten Noventa 12, its, sass su: imm 1o' Cl'aifs.' (c1. 10s-23) Y Myinvention relates to structural members and has to do more particularlywith a composite or lattice truss sodesigned as to be especially adaptedfor wood fabrication.

A particular object of my invention is to provide a truss of exceptionalstrength although of moderate cost.

A further object is. to provide such a device which may be made whollyout of wood and which will be simple in design andV inexpensivetofabricate, and especially adaptable as a roof support.

Referring nowto the drawings forming apart of this specification andillustrating a preferred embodiment of my invention:

Fig.. 1 is a side elevational View of a truss embodyingmy invention;

Fig. 2 is a fragmentary sectionalview onan enlargedscale takensubstantially along the line 2-2 of Fig. 1

Eig. 3 isa sectionalvew taken' substantially along the line 3-3 of Fig.l;

Fig; 4 is anl end elevation of the same;

Fig. 5 is a sectionaiview taken substantially along the line'S-S of Fig.1;' and Figs. 6, 7,' and 8 are fragmentary elevational views ofelements' forming part of the composite truss constituting my invention.

Trusses embodying my invention preferably comprise a' plurality ofskeleton truss members indicated by the numerals- Illa, Illb, IOC, andIl'ld (see Fig. 3'). Eachof these members justreferred to4comprisesa'straight beam I2 v and an arcuate beam' I5; These beamsY maybe forme'dof4 a single length of wood or other suitable material, or ofaplur'ality of lengths. The straight beams I 2 are preferably increasedin depth at their ends, as indicated at I3. Said increase of depth maybe accomplished as shown, by means of separate lengths of material, orby providing integral enlarged end portions in the beams I2. The ends ofthe beams I2 are joined by the arcuate spans or girders I5, whichmembers likewise may be formed of a single length or of several lengthsof material. 45 Secured between two of the skeleton members, say themembers Id and IIJc, is a plurality of oblique struts I'I (Fig. 6). Thespaces between said struts are lled by means of spacing members I8 onboth the straight beam I2 and arcuate girder I5. The spacing members I8as seen best in Fig. 2, are preferably equal in thickness to the strutsI'I.

The struts I1 are preferably disposed at an angle of 45 degrees and itwill be seen that I have 55 spaced the struts I1 closer togetheradjacent the ends Yof thetrllturalunit,as `seenn Fig. 6, than inthemiddle. This is for the reason that I havefonnd thatthefailureAofvtrusses of this type occurs most lfrequently adjacent-the ends.

, Secured between theskeleton trusses Ic and HlbisV a p111ra1ity-0fvertical struts 20. .These struts are also Yspaced closertogetheradjacent therends of.,the truSSLhan inthe middle, as seen clearly.inFig.T7 and spacers :ZI are preferably provided` between saidjyerticalstruts 20.

Disposedbetween theskeleton trusses Ina and I Ub is a pluralityofyobliquestruts 25 (Fig. 8), these struts being likewise preferablyarranged at. an angle offl degrees and oppositely to. struts I 'I andspaced closer together adjacent the ends of the truss. Spacers 26 areprovided between thei ends .of thestruts 25.

. At seen best in Fig. 1, the struts are preferably so,arrangedlongitudinally that three struts,.i. e., two of the obliquestruts extending in Aopposite directions and `an .interposed .verticalstrut, cross each other at various points throughout the length of thetruss as, .forexampla at v28, saidY crossing points lying in a commonline for the major. part of Ithe'trusslength. .At these points llerblocks `3D are inserted and the struts and'blocks are tied together'. asby means' of nails 3| (Fig. 3). .Obviously,othe`r.secu'ring devicesmight be used, such af'V screws,l bolts,` etc... and such securingdevices are usedthrou'gout the entire structure for joining thevariousmembers. y

The aicu'ateportionof the4 truss is preferably provided' with one"ormore longitudinal tie members 33 which serve'tc bindf the variouscomposite elements' of the' arch'a's" seen" best in Figs. 3V and 5.

- It will be apparent that, although my invention is especiallyapplicable to wood fabrication, it may be used for various othermaterials, such as, for example, steel, in which case joining may beaccomplished by welding or other suitable means.

Tests show that structural members embodying my invention withstand muchheavier loads before failure than any similar structural members withwhich I am familiar.

Various changes coming within the spirit of my invention may suggestthemselves to those skilled in the art, and hence I do not wish to belimited to the specific embodiment shown or uses mentioned except to theextent indicated in the appended claims which are to be interpreted asbroadly as the state of the art will permit.

I claim: l. A structural member comprising a plurality of pairs ofskeleton trusses arranged in spaced parallel relation, each truss havinga straightportion and an arcuate portion, and a series of strutsdisposed between each pair of adjacent skeleton trusses, said strutscomprising two series of oblique struts extending angularly to eachother, and a series of vertical struts, members of the three seriescrossing at points throughout substantially the entire length of thestructural member, and means securing said oblique and Vertical strutstogether at said crossing points.

2. A device as dened in claim 1 wherein each series of oblique struts isdisposed at an angle of 45 degrees.

3. A device as defined in claim 1 wherein the struts are more closelyspaced adjacent the ends of the structural member than in the middlethereof.

4. A structural member comprising a plurality of pairs of skeletontrusses arranged in spaced parallel relation, each of said trussescomprising a straight member and an arcuate member having their endsjoined, a series of struts secured between a pair of said skeletontrusses and arranged at an angle of 45 degrees, another series of strutsdisposed between another pair of skeleton trusses and perpendicular tosaid first series of struts, a series of vertical struts disposedbetween another pair of skeleton trusses and arranged intermediate ofsaid diagonal struts, members of the three series of struts crossing atpoints throughout substantially the entire length of the structuralmember, and means securing said struts together at said crossing points.

5. In a device as dened in claim 1, members disposed between the ends ofthe struts of each series and substantially filling the spacetherebetween.

6. In a device as dened in claim 4, members disposed between the ends ofthe struts of each series and substantially filling the spacetherebetween. Y v

7. A structural member comprising a plurality of pairs of skeletontrusses arranged in spaced parallel relation, each truss having astraight portion and an arcuate portion, and a series of struts disposedbetween eachpair of adjacent skeleton trusses, said struts comprisingtwo series of oblique struts extending angularly to eachother, and aseries of vertical struts, members of the three series crossing atpoints throughout substantially the entire j. length of the structuralmember, means securing said oblique and Vertical struts together at saidcrossing points, and a longitudinal tie member having a flat sideoverlying substantially the full length of and secured to the outeredges of said arcuate portions.

8. A structural member comprising a plurality of pairs of skeletontrusses arranged in spaced parallel relation, each truss having astraight portion and an arcuate portion, and a series of struts disposedbetween each pair of adjacent skeleton trusses, said struts comprisingtwo series of oblique struts extending angularly to each other, and aseries of vertical struts, members of the three series crossing atpoints throughout substantially the entire length of the structuralmember, and means securing said oblique and vertical struts together atsaid crossing points, the ends of said straight portion being of greaterdepth than and projecting below the lower longitudinal edge of theintermediate part of said straight portion.

9. A structural member comprising a plurality of pairs of skeletontrusses arranged in spaced parallel relation, each truss having astraight portion and an arcuate portion, and a series of struts disposedbetween each pair of adjacent skeleton trusses, said struts comprisingtwo series of oblique struts extending angularly to each other, and aseries of vertical struts, members of the three series crossing atpoints throughout substantially the entire length of the structuralmember, and means securing said oblique and vertical struts together atsaid crossing points, said struts being more closely spaced adjacent theends of the structural member than in the middle thereof, said points ofthe relatively remotely spaced struts lying in a straight line parallelto said straight portion.

10. A structural member comprising a plurality of pairs of skeletontrusses arranged in spaced parallel relation, each truss having astraight portion and an arcuate portion, and a series of struts disposedbetween each pair of adjacent skeleton trusses, said struts comprisingtwo series of oblique struts extending angularly to each other, andaseries of vertical struts, members of the three series crossing atpoints throughout substantially the entire length of the structuralmember, and means securing said oblique and vertical struts together atsaid crossing points, said strutsV being more closely spaced adjacentthe ends of the structural member than in the middle thereof, saidseries of struts constituting the sole connecting means in the spacebetween said portions.

` WILLIAM F. DAVIS.

